quote.c

   1 #include "cache.h"
   2 #include "quote.h"
   3
   4 /* Help to copy the thing properly quoted for the shell safety.
   5  * any single quote is replaced with '\'', any exclamation point
   6  * is replaced with '\!', and the whole thing is enclosed in a
   7  *
   8  * E.g.
   9  *  original     sq_quote     result
  10  *  name     ==> name      ==> 'name'
  11  *  a b      ==> a b       ==> 'a b'
  12  *  a'b      ==> a'\''b    ==> 'a'\''b'
  13  *  a!b      ==> a'\!'b    ==> 'a'\!'b'
  14  */
  15 #undef EMIT
  16 #define EMIT(x) do { if (++len < n) *bp++ = (x); } while(0)
  17
  18 static inline int need_bs_quote(char c)
  19 {
  20         return (c == '\'' || c == '!');
  21 }
  22
  23 static size_t sq_quote_buf(char *dst, size_t n, const char *src)
  24 {
  25         char c;
  26         char *bp = dst;
  27         size_t len = 0;
  28
  29         EMIT('\'');
  30         while ((c = *src++)) {
  31                 if (need_bs_quote(c)) {
  32                         EMIT('\'');
  33                         EMIT('\\');
  34                         EMIT(c);
  35                         EMIT('\'');
  36                 } else {
  37                         EMIT(c);
  38                 }
  39         }
  40         EMIT('\'');
  41
  42         if ( n )
  43                 *bp = 0;
  44
  45         return len;
  46 }
  47
  48 void sq_quote_print(FILE *stream, const char *src)
  49 {
  50         char c;
  51
  52         fputc('\'', stream);
  53         while ((c = *src++)) {
  54                 if (need_bs_quote(c)) {
  55                         fputs("'\\", stream);
  56                         fputc(c, stream);
  57                         fputc('\'', stream);
  58                 } else {
  59                         fputc(c, stream);
  60                 }
  61         }
  62         fputc('\'', stream);
  63 }
  64
  65 char *sq_quote_argv(const char** argv, int count)
  66 {
  67         char *buf, *to;
  68         int i;
  69         size_t len = 0;
  70
  71         /* Count argv if needed. */
  72         if (count < 0) {
  73                 for (count = 0; argv[count]; count++)
  74                         ; /* just counting */
  75         }
  76
  77         /* Special case: no argv. */
  78         if (!count)
  79                 return xcalloc(1,1);
  80
  81         /* Get destination buffer length. */
  82         for (i = 0; i < count; i++)
  83                 len += sq_quote_buf(NULL, 0, argv[i]) + 1;
  84
  85         /* Alloc destination buffer. */
  86         to = buf = xmalloc(len + 1);
  87
  88         /* Copy into destination buffer. */
  89         for (i = 0; i < count; ++i) {
  90                 *to++ = ' ';
  91                 to += sq_quote_buf(to, len, argv[i]);
  92         }
  93
  94         return buf;
  95 }
  96
  97 /*
  98  * Append a string to a string buffer, with or without shell quoting.
  99  * Return true if the buffer overflowed.
 100  */
 101 int add_to_string(char **ptrp, int *sizep, const char *str, int quote)
 102 {
 103         char *p = *ptrp;
 104         int size = *sizep;
 105         int oc;
 106         int err = 0;
 107
 108         if (quote)
 109                 oc = sq_quote_buf(p, size, str);
 110         else {
 111                 oc = strlen(str);
 112                 memcpy(p, str, (size <= oc) ? size - 1 : oc);
 113         }
 114
 115         if (size <= oc) {
 116                 err = 1;
 117                 oc = size - 1;
 118         }
 119
 120         *ptrp += oc;
 121         **ptrp = '\0';
 122         *sizep -= oc;
 123         return err;
 124 }
 125
 126 char *sq_dequote(char *arg)
 127 {
 128         char *dst = arg;
 129         char *src = arg;
 130         char c;
 131
 132         if (*src != '\'')
 133                 return NULL;
 134         for (;;) {
 135                 c = *++src;
 136                 if (!c)
 137                         return NULL;
 138                 if (c != '\'') {
 139                         *dst++ = c;
 140                         continue;
 141                 }
 142                 /* We stepped out of sq */
 143                 switch (*++src) {
 144                 case '\0':
 145                         *dst = 0;
 146                         return arg;
 147                 case '\\':
 148                         c = *++src;
 149                         if (need_bs_quote(c) && *++src == '\'') {
 150                                 *dst++ = c;
 151                                 continue;
 152                         }
 153                 /* Fallthrough */
 154                 default:
 155                         return NULL;
 156                 }
 157         }
 158 }
 159
 160 /*
 161  * C-style name quoting.
 162  *
 163  * Does one of three things:
 164  *
 165  * (1) if outbuf and outfp are both NULL, inspect the input name and
 166  *     counts the number of bytes that are needed to hold c_style
 167  *     quoted version of name, counting the double quotes around
 168  *     it but not terminating NUL, and returns it.  However, if name
 169  *     does not need c_style quoting, it returns 0.
 170  *
 171  * (2) if outbuf is not NULL, it must point at a buffer large enough
 172  *     to hold the c_style quoted version of name, enclosing double
 173  *     quotes, and terminating NUL.  Fills outbuf with c_style quoted
 174  *     version of name enclosed in double-quote pair.  Return value
 175  *     is undefined.
 176  *
 177  * (3) if outfp is not NULL, outputs c_style quoted version of name,
 178  *     but not enclosed in double-quote pair.  Return value is undefined.
 179  */
 180
 181 static int quote_c_style_counted(const char *name, int namelen,
 182                                  char *outbuf, FILE *outfp, int no_dq)
 183 {
 184 #undef EMIT
 185 #define EMIT(c) \
 186         (outbuf ? (*outbuf++ = (c)) : outfp ? fputc(c, outfp) : (count++))
 187
 188 #define EMITQ() EMIT('\\')
 189
 190         const char *sp;
 191         unsigned char ch;
 192         int count = 0, needquote = 0;
 193
 194         if (!no_dq)
 195                 EMIT('"');
 196         for (sp = name; sp < name + namelen; sp++) {
 197                 ch = *sp;
 198                 if (!ch)
 199                         break;
 200                 if ((ch < ' ') || (ch == '"') || (ch == '\\') ||
 201                     (quote_path_fully && (ch >= 0177))) {
 202                         needquote = 1;
 203                         switch (ch) {
 204                         case '\a': EMITQ(); ch = 'a'; break;
 205                         case '\b': EMITQ(); ch = 'b'; break;
 206                         case '\f': EMITQ(); ch = 'f'; break;
 207                         case '\n': EMITQ(); ch = 'n'; break;
 208                         case '\r': EMITQ(); ch = 'r'; break;
 209                         case '\t': EMITQ(); ch = 't'; break;
 210                         case '\v': EMITQ(); ch = 'v'; break;
 211
 212                         case '\\': /* fallthru */
 213                         case '"': EMITQ(); break;
 214                         default:
 215                                 /* octal */
 216                                 EMITQ();
 217                                 EMIT(((ch >> 6) & 03) + '0');
 218                                 EMIT(((ch >> 3) & 07) + '0');
 219                                 ch = (ch & 07) + '0';
 220                                 break;
 221                         }
 222                 }
 223                 EMIT(ch);
 224         }
 225         if (!no_dq)
 226                 EMIT('"');
 227         if (outbuf)
 228                 *outbuf = 0;
 229
 230         return needquote ? count : 0;
 231 }
 232
 233 int quote_c_style(const char *name, char *outbuf, FILE *outfp, int no_dq)
 234 {
 235         int cnt = strlen(name);
 236         return quote_c_style_counted(name, cnt, outbuf, outfp, no_dq);
 237 }
 238
 239 /*
 240  * C-style name unquoting.
 241  *
 242  * Quoted should point at the opening double quote.
 243  * + Returns 0 if it was able to unquote the string properly, and appends the
 244  *   result in the strbuf `sb'.
 245  * + Returns -1 in case of error, and doesn't touch the strbuf. Though note
 246  *   that this function will allocate memory in the strbuf, so calling
 247  *   strbuf_release is mandatory whichever result unquote_c_style returns.
 248  *
 249  * Updates endp pointer to point at one past the ending double quote if given.
 250  */
 251 int unquote_c_style(struct strbuf *sb, const char *quoted, const char **endp)
 252 {
 253         size_t oldlen = sb->len, len;
 254         int ch, ac;
 255
 256         if (*quoted++ != '"')
 257                 return -1;
 258
 259         for (;;) {
 260                 len = strcspn(quoted, "\"\\");
 261                 strbuf_add(sb, quoted, len);
 262                 quoted += len;
 263
 264                 switch (*quoted++) {
 265                   case '"':
 266                         if (endp)
 267                                 *endp = quoted + 1;
 268                         return 0;
 269                   case '\\':
 270                         break;
 271                   default:
 272                         goto error;
 273                 }
 274
 275                 switch ((ch = *quoted++)) {
 276                 case 'a': ch = '\a'; break;
 277                 case 'b': ch = '\b'; break;
 278                 case 'f': ch = '\f'; break;
 279                 case 'n': ch = '\n'; break;
 280                 case 'r': ch = '\r'; break;
 281                 case 't': ch = '\t'; break;
 282                 case 'v': ch = '\v'; break;
 283
 284                 case '\\': case '"':
 285                         break; /* verbatim */
 286
 287                 /* octal values with first digit over 4 overflow */
 288                 case '0': case '1': case '2': case '3':
 289                                         ac = ((ch - '0') << 6);
 290                         if ((ch = *quoted++) < '0' || '7' < ch)
 291                                 goto error;
 292                                         ac |= ((ch - '0') << 3);
 293                         if ((ch = *quoted++) < '0' || '7' < ch)
 294                                 goto error;
 295                                         ac |= (ch - '0');
 296                                         ch = ac;
 297                                         break;
 298                                 default:
 299                         goto error;
 300                         }
 301                 strbuf_addch(sb, ch);
 302                 }
 303
 304   error:
 305         strbuf_setlen(sb, oldlen);
 306         return -1;
 307 }
 308
 309 void write_name_quoted(const char *prefix, int prefix_len,
 310                        const char *name, int quote, FILE *out)
 311 {
 312         int needquote;
 313
 314         if (!quote) {
 315         no_quote:
 316                 if (prefix_len)
 317                         fprintf(out, "%.*s", prefix_len, prefix);
 318                 fputs(name, out);
 319                 return;
 320         }
 321
 322         needquote = 0;
 323         if (prefix_len)
 324                 needquote = quote_c_style_counted(prefix, prefix_len,
 325                                                   NULL, NULL, 0);
 326         if (!needquote)
 327                 needquote = quote_c_style(name, NULL, NULL, 0);
 328         if (needquote) {
 329                 fputc('"', out);
 330                 if (prefix_len)
 331                         quote_c_style_counted(prefix, prefix_len,
 332                                               NULL, out, 1);
 333                 quote_c_style(name, NULL, out, 1);
 334                 fputc('"', out);
 335         }
 336         else
 337                 goto no_quote;
 338 }
 339
 340 /* quoting as a string literal for other languages */
 341
 342 void perl_quote_print(FILE *stream, const char *src)
 343 {
 344         const char sq = '\'';
 345         const char bq = '\\';
 346         char c;
 347
 348         fputc(sq, stream);
 349         while ((c = *src++)) {
 350                 if (c == sq || c == bq)
 351                         fputc(bq, stream);
 352                 fputc(c, stream);
 353         }
 354         fputc(sq, stream);
 355 }
 356
 357 void python_quote_print(FILE *stream, const char *src)
 358 {
 359         const char sq = '\'';
 360         const char bq = '\\';
 361         const char nl = '\n';
 362         char c;
 363
 364         fputc(sq, stream);
 365         while ((c = *src++)) {
 366                 if (c == nl) {
 367                         fputc(bq, stream);
 368                         fputc('n', stream);
 369                         continue;
 370                 }
 371                 if (c == sq || c == bq)
 372                         fputc(bq, stream);
 373                 fputc(c, stream);
 374         }
 375         fputc(sq, stream);
 376 }
 377
 378 void tcl_quote_print(FILE *stream, const char *src)
 379 {
 380         char c;
 381
 382         fputc('"', stream);
 383         while ((c = *src++)) {
 384                 switch (c) {
 385                 case '[': case ']':
 386                 case '{': case '}':
 387                 case '$': case '\\': case '"':
 388                         fputc('\\', stream);
 389                 default:
 390                         fputc(c, stream);
 391                         break;
 392                 case '\f':
 393                         fputs("\\f", stream);
 394                         break;
 395                 case '\r':
 396                         fputs("\\r", stream);
 397                         break;
 398                 case '\n':
 399                         fputs("\\n", stream);
 400                         break;
 401                 case '\t':
 402                         fputs("\\t", stream);
 403                         break;
 404                 case '\v':
 405                         fputs("\\v", stream);
 406                         break;
 407                 }
 408         }
 409         fputc('"', stream);
 410 }